#include<bits/stdc++.h>
using namespace std;
int main()
{
    freopen("duel.in","r",stdin);
    freopen("duel.out","w",stdout);

    int n,a[1000005]={},c=0;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
    if(n%2==0) cout<<n/2;
    if(n%2!=0) cout<<n/2;
    fclose(stdin);
    fclose(stdout);
    return 0;
}
